Python Classes — Complete Cheat Sheet

What is a Class?

A class is a blueprint for creating objects. It defines the properties (variables) andmethods (functions) that objects created from it will have.

Think of a class as a template. Objects are individual copies created from this template.

Why Use Classes?

• Organize code into structures
• Reuse code easily
• Follow OOP (Object-Oriented Programming)
• Model real-world things like Car, Student, Product, etc.

Basic Class Syntax

A simple class with a class attribute:

class MyClass:
  x = 10

MyClass is a class. Inside it, x is a class attribute.

Creating an Object from a Class

obj = MyClass()
print(obj.x)

obj is an object created from MyClass. Access its attributes using dot notation.

Class with a Method

A class can have functions called methods:

class Person:
  def greet(self):
    print("Hello, I am a Person")

p = Person()
p.greet()

Every method must include self as the first parameter. It refers to the current object.

Class vs Object

Best Practices

• Use PascalCase for class names (e.g., StudentData)
• Use self to access attributes inside methods
• Group related functions and data inside classes
• Keep class names meaningful and descriptive